Project Summary/Abstract Study Title: A Pilot/Supportive Study of RC-2 to be Used in the Treatment of Canine Lymphoma Experimental Design: This is an exploratory study designed as a prospective, open label, single site, single arm, clinical field study. Objectives/Purpose of study: The purpose of this clinical trial is to determine the safety and efficacy of the drug, RC-2, in client-owned canines nave or relapsed Stage II-V lymphoma. Client owned dogs meeting the enrollment/eligibility criteria will be recruited from the cases presented to the Texas A M Veterinary Oncology Service. All dogs must have progressive disease upon entry into the study. The primary efficacy variable will be the time to tumor progression (TTP). Other variables recorded and reported include ORR (overall response rate- partial remission or better), the disease control rate (stable disease or better), and the duration of response (DOR). Variables will be reported separately for nave versus relapsed patients. The secondary objective is to determine the tolerability of the drug over a 3-month period in all dogs by recording and reporting in a real time fashion any adverse events. Study Site: Texas A M University, College of Veterinary Medicine, Small Animal Clinical Sciences Study Dogs: A minimum of 15 client owned dogs with newly diagnosed or first relapse stage II - IV lymphoma will be enrolled in this study. Dogs must meet all eligibility criteria and no exclusion criteria. Justification: Lymphoma is the most common malignancy diagnosed in canines representing up to 24% of all neoplasms seen in dogs. This disease is almost inevitably fatal with the median survival time for dogs receiving aggressive combination chemotherapy at 12 months. New therapeutic approaches, such as RC-2, are desperately needed to improve upon current disease outcomes. Study Standards and Ethics: This study protocol will be reviewed by the Institutional Animal Care and Use Committee at TAMU. Absolute compliance with this committee and its suggestions will be met before, during and after the study is performed. Written informed client consent will be obtained from each enrolled dog's owner before the dog can be enrolled. The welfare, treatment and care of the study animals will be ensured by the veterinary staff at the TAMU CVM Small Animal Clinic